Revolutionising energy storage: Acoustic modulated flame pyrolysis of sesame oil for enhanced electrocapacitive carbon NanoOnions

This work presents a cost-effective synthesis method for Carbon Nano Onions (CNOs) by combining flame pyrolysis of sesame oil with acoustic modulation at 432 Hz. XRD and Raman spectra confirm CNO formation. The introduction of acoustic waves serves to influence flame dynamics and carbon nucleation behaviour, promoting desirable structural changes in the resulting CNOs. Structural analysis confirms that acoustic modulation enhances particle sphericity, increases homogeneity, and reduces average particle diameter to 30.54 nm. Cyclic voltametric analysis demonstrated a significant performance enhancement: the specific capacitance at a scan rate of 0.1 V increased from 158 F/g for the unmodulated sample to a remarkable 245 F/g for the acoustically modulated CNOs. Electrochemical impedance spectroscopy (EIS) further supported this, with the modulated CNOs showing a near-vertical plot in the low-frequency region. The GCD analysis shows good cycling stability with 60 % columbic efficiency. This study successfully demonstrates a sustainable and controllable route for CNO fabrication, opening new avenues for advancing robust, high-performance energy storage technologies.